Road grader



July 14, 1925. 1,545,985

c. E. STAHL ROAD GRADER Filed June 2, 1921 4 Sheets-Sheet 2 I veqkar July 14, 1925. 1,545,985

0. E. STAHL ROAD GRADER Filed June 2, 1921 4 Sheets-Sheet 5 Cigar/e; (Sf'al/ July 14, 1925. 1,545,985

c. E. STAHL ROAD GHADER Filed June 2, 1921 4 Sheets-Sheet 4 Car/ej 6604/ IlllllllllllllllllilllllilllllllllllllllliI|lll|ll||l|!!|1 @zfieaa:

$ 2 MW a U% Patented July 14, 1925.

UNITED STATES CHARLES E. STAHL, OF NEWTON, IOWA.

ROAD GRADER.

Application filed June 2, 1921.

T all whom it may concern:

Be it known that I, CHARLES E. STAHL, citizen of the United States, residing at Newton, in the county of Jasper and State of Iowa, have invented certain new and useful Improvements in a Road Grader; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to road graders, its general objects being those of providing a self-propelling road grader adapted to operate continuously and capable of excavating the surface portions of a road with such an exactness as to eliminate hand labor.

In grading roads to highly desirable levels and contours, and particularly in preparing such a road for receiving a concrete pavement, it is important that the grading should be done with a high degree of precision. IV here no surface coating of concrete or the like is to be added, this importance resides 3 largely in the appearance and proper drain age which is intimately associated with the wearing relations of the road; while in the case of roads which are to be concreted, accuracy of the grading also makes a large diffcrence in the cost. For example, if some portions of the road are left even half an inch too high, the resulting diminution in the thickness of the foundation for the concrete may make this foundation inadequate It?! and may bar the work from being approved.

Likewise, if portions are too low, a corresponding excess of material will be needed for the concrete foundation, thereby increasing the cost of this foundation.

In modern road building even variations of a half inch counts along these lines, hence it has heretofore been customary to employ hand labor for finishing the work of the grading after the latter has been roughed out by suitable horse-driven or power-driven equipment. My invention aims to provide a road grading machine so arranged that it can readily be adjusted for securing the accuracy required for this finer grading after 513 the grade has been roughed out by means of shovels or the like. For this purpose, my invention aims to provide a road grader Serial No. 474,519.

(desirably of a self-propelling type) which will continuously trim down the top ofthe road to a predetermined-heightand lateral inclination in relation to that upon which the supporting portion of the grader is traveling; which will'continuously pick up the soil removed by it and convey the same beyond the machine into some adjacent wagon or other receptacle; which will finish the grading by a suitable scraping operation; which will permit of fan easy and accurate adjusting of both the height and'the inclination of the grade thusefi'ected and which will not permit the excavating mechanism to swerve the grader'out of'the course in which it, can easily be steered."

More particularly, my invention aims to provide a. road grader equipped at its forward end with means for excavating to the desired grade and equipped with means behind the excavating means for scraping the resulting grade to a corresponding and smooth finish. It also aims to provide simple and effective mechanism for simultaneously raising and lowering the excavating and scraping means and means for tilting both of the said means in either direction laterally of the machine; to provde simple and eflcctive means for preventing the resistance to the excavating from deflecting the grader out of its path, and to provide means for adjusting the operation of the said defiedlion-preventing means in proportion to the hardness of the soil. Furthermore, I aim to provide a road grading machine employing a bucket excavating system acting transversely of the path of the grader, to provide effective means for insuring a cut of the desired contour by the said buckets, to provide conveniently arranged means for transferring the dirt excavated by the buckets to suitable conveyers, to provide scraping means behind the bucket system for finishing the resulting grading, and to provide path-maintaining means ahead of the bucket system for preventin the resistance-to the excavation of the soil y the buckets from defleeting the grader out of its intended path.

For this latter purpose I desirably provide the said path-maintaining means in the form. of cutters entering the soil ahead of the bucket excavators and shape these cutters for effectively resisting the back thrust on the excavating buckets. I also provide simple means for adjusting the depth to which these cutters enter the soil in dproportion to the hardness of the soil, @an mountthese cutters so that they will be raised, lowered or titlted in response to the adjustment of the bucket excavator system and of the scraping means. Furthermore, I aim to provide an effective mounting for the entire road grading machine, and to arrange .this mounting so as to prevent the wei ht of the machine from marring the graded-surface; also .to provide simple and easily controlled 7 means for operating all of the above named mechanisms including the said adjusting means. Still "further and more-detailed objects will appear from the following specification and 'fromthe accompanying drawin s, in which Jig. 1 is a sideelevat ionof a road grader enihocl yingjmy invention, showing the same as it appears in 'operationwhen taking a relatively deep cut 'inlight soil.

Fig. '2 ism; plan view of the same machine taken fromthelijne2-2 in Fig. 1.

Fig. 3 a front elevation of the same.

Fig. 4 is'a somewhat diagrammatic view showing theldriving connections between the en ine-and various parts oflthe mechanism.

i ig. 5 is a plan view, partlyin section and showing the driving connection for the hoisting mechanism.

In the illustrated embodiment, the road grader of my invention comprises a tractor having at each side a-series of link-jointed tread members 1 whose links are intermeshe-d with teeth on driving wheels 2. The bearings for these wheels support side bars 3 which carry 'the frame of the machine, and this frame desirably includes a pair of forward vertical corner posts 3 and a corresponding pair of rear posts or risers 5. Mounted within the frame work between the said posts is a suitable source of power, such as a gasoline engine 75 having its shaft 6 connected means hereafter described both 'to the tractor wheels 2 and to other portions of the mechanism of the grader.

Generally speaking, the grader for which the said tractor arrangement forms the propelling mechanism comprises an adjustably supported endless system of buckets 7 mounted at the front of the machine and ar- 3 ranged for dumping the excavated soil into a hopper 8; a longitudinal conveyer 9 upon which the soil is dumped through the said hopper; and a transverse conveyer 10 arranged for receiving the soil from the rear end of the conveyor 9 and for delivering the same to any suitable receptacle, such as the body 11 of a wagon driven along side of the machine.

For the excavating or bucket conveyer system, 1 desirably employ a series of buckets 7 supported by endless link chains 12 which are trained over sprocket Wheels 13. The links 12 carrying the buckets may be freely trained between the heads 13 along their upper stretches, but desirably are kept with their cutting edges alined in a common plane along the lower stretch of the said links by idlers -14 rotatably mounted on a normally horizontal bar 15 extending transversely of the machine at the front of the latter, so that these idlers will guide the lowermost buckets while actively excavating, thereby accurately determining the depth and contour of the cut effected by these buckets. Thesaid cross bar 15 forms a part of a suspension frame which is adjustably mounted on a main frame of the machine and which is adapted to beraised or lowered by power driven means as hereafter described. To afford such mounting, I desirabLyprovide risers 16 respectively in front of theforward posts 3 and spaced from the latter so as to cooperate with the posts 3 in affording guides for flanged wheels 17 which are pivoted to the auxiliary frame of which the bar 15 forms apart. Then I connect this frame by flexible members 18 to a pair of drums .19 respectively geared through a pair of .worm wheels and through corresponding worms to a pair of shafts adapted to be driven in relatively opposite directions by the engine 75 as more fully described hereafter.

For actuating thesedrums which control the elevation and tilting of the said carrier frame, for propelling the vehicle and for operating the bucket excayator system, I desirably employ a single engine together with .a series of clutches respectively controlling the different connections. For this purpose, .I am here showing a series of desirable driving connections, parts of which have been omitted in Fig. 1 and Fig. 2 to avoid confusion, and some of which can be more easily traced through the diagrammatic views of Fig. 4 and Fig. 5.

Starting at the engine as the common source of power, the engine shaft 6 is connected through gears 53 and 54 with ai secondary shaft 26, which secondary shaft is connected through link chains 64 and 65 with the bucket excavator system as shown in Fig. 3 the link chain 64 being of such a length as to remain substantially taut during the raising or lowering of the carrier of the machine, which raising or lowering varies the height of the shaft carrying the sprockets which connect the said chains 6% and 65. The secondary shaft 26 is also connected through a link chain 66 with sprockets respectively fast upon two worm shafts 24, each of the latter being geared through bevel gears 27 and with a bevel gear 28. The gears 27 are fast respectively on the worm shafts 24, while the gears 28 and 30 are loose upon the shafts carrying the same, the two intermediate. gears 30 being here shown as mounted on a common shaft 67. Each worm shaft 24 carries a clutch 29 whereby this shaft can be latched either to the bevel gear 27 or to the oppositely rotating bevel gear 28 (there: clutches 29 being diagrammatically shown in Fig. so that either of the said worm shafts can be driven independently of the other and in either direction. The worm 21 on each worm shaft meshes with a worm which is fastened to a drum 19, both of these drums 19 being rotatably mounted on astationary shaft 23 which extends horizontally across the front of the machine near .the top of the latter.

These drums 19 have already been described as respectively connected by the hoisting cables 18 with the suspension frame 15 which carries the excavator system together with the disk harrows and the scraper. By throwing either clutch 29 into engagement with one or the other of the bevel gears 27 and 28 adjacent thereto, the cable 18 at that side of the machine can be wound or unwound, thereby raising or lowering that side of the suspension frame 15. Consequently, by moving the clutches 29 simultaneously and in the same direction, the frame 15 can be raised or lowered vertically; or, this frame can be tilted by actuating one of the clutches 29 independently of the other.

For propelling the vehicle, I am showing driving connections including a link chain 64 which connects the secondary shaft 26 with a shaft 68, the latter having a pinion 56 fast upon it. This pinion 56 is disposed for meshing with a gear which is slidably keyed to a drive shaft 69, the latter being connected through a train of gears 57, 58, 59 and to a shaft 52 carrying a mitre gear 71 which rotates two bevel gears 61 and 62 in opposite directions. The bevel gears 61 and 62 are both rotatably mounted on a tractor shaft 46, and either one may be latched to the said shaft by correspondingly moving a clutch 73, thereby causing the saidtrain of gears to rotate the drive shaft 46 in either direction. This drive shaft carries near each end a sprocket 47 connected by a link chain 45 with the tractor arrangement at the adjacent side of the machine and each sprocket 47 can be interlocked with the shaft 46 by means of an adjacent clutch 51. Consequently, by sliding the gear 55 either into or out of mesh with the pinion 56, the tractor drive can be started and stopped. Likewise, by moving the clutch 73, the driving connection to the tractor arrangement can be reversed in direction, and by manipulating the clutches 51 the differential drive needed for turning corners or otherwise deviating from a straight path can be secured.

In practice, the low tractor speed obtained with the just recited connections is desirable when the machine is excavating, but is too slow for propelling the vehicle when running idle, hence I desirably also provide simple means for connecting the tractor drive without the speed reduction between the pinion 56 and the sliding gear 55. For this purpose, I am showing the secondary shaft 26 as having fastened to it a gear 54 meshing with a pinion .53, the latter being disposed for intermeshiiig with the sliding gear 55 when the latter is slid to the right from its medial or idle position of Fig. 4. WV hen the gear 55 is thus slid over, the shaft 68 runs idle and the train of gears starting with the gears 57 and 58 is driven at a much higher speed than before, thereby affording the higher rate of propulsion needed when the machine is to be moved from place to place. I

At the other end of the engine shaft 1 provide suitable connections to the conveyers, which connections will be evident from Fig. l and need not be described in detail as they will readily 'be understood by those versed in machinery of this general class.

In operation, the suspension frame, to gether with the bucket excavator system and other elements carried by the said frame are raised entirely clear of the road surface while the machine is propelled by its own power, this being done with the gear 53 intermeshing with the sliding gear 55, so as to propel the tractor portion of the machine at the relatively high speed in which it can rapidly cover ground when idle as to any grading operation. As soon as a desired starting point has been reached, the clutches 29 are suitably operated so as to lower the suspension frame 15 to a sufficient depth for causing the inclined bottoms of the bucket conveyers to take a sligl-it cut in advance of the tractor treads. These treads will therefore be sloped downwardly correspondingly when they reach the excavated portion and the resulting inclination will cause the grader to dig deeper as the machine leans forward. As soon as the desired depth has been reached, the suspension frame is correspondingly raised so that the machine will thereafter continue to travel horizontally or with a substantially uniform depth of cutting.

Since the buckets act laterally of the machine during their excavating, the resistance or back thrust on these buckets would tend to move the bucket system in the opposite direction from that in which it is propelled by power and hence would swing the entire machine out of its desired course. To avoid this, I provide suitable means at the front of the machine for resisting this side thrust, and desirably employ a series of disk harrows for this purpose. These disk harrows prefe'rably are carried also by the adjustably mounted fra'ine =-'S0"as to be raised "and lowered *with the latter anddesirably are supported in a Waytha't will pernli't them to yield in case theystrike relatively "tough soil. Thus, Fig. 1 shows "a her-row shaft 38 pivofied between- 21 pairof levers 39 which levers are pivoted 5 at their rear ends'to 'portionso'f the auxiliary frame 15. Each of'these levers is connected intermedi- "ate of its ends to a-pl'unger 40 which extends slidably through" a bearing '41 on the frame 1 5 and which is continuously pressed downward by aspring'42. Thus arranged, it ivillbe evident' from Fig. 1 that the spring 42 wilt continuouslyu'rge the shaft 38 downwardly, thus "causing e'ach h'arrow "disk 43 "to cut-into th'e'soil'44, although permitting the disks "to lift the shaft against the pres- "s ureof the springs42 in'ca'se they strike unusually hard soil. The depth to which these disks-enter the soil 'will therefo're vary with'thehardness dfthe*latten thereby p're- :ventin'ghnd-ue friction and wast of p'ower. To mak the 'harrow disks "all the more effective -in resisting *th'e side "thrust due to the bucket system,- I desir'ably employ con- -caved disks disposed with their -conv'exed fac'e's iiij tlie'sam'e directionwith the excavating buckets and hence offering their conoaved faces for resisting the thrust.-

'By employing a large 'nin nb'er "or excavator buckets and propelling the'm'achineas a whole at a quite slowspe'ed in proportion i -t0'the'rateat which the buckets move transversely off-the grader, *Ican obta'in'such a 'gradu'aland delicate cutting action as will enable me to effect th'e'd'esired grading with 'nnicety comparable to hand Work. More over, I desirably supplement this bucket excavating by a's'cra'pcr 74 fastened to the suspension frame '15 and 'eiitending'transversely of thc grader directly behind the buckets and in horizontal aline'inent with the cut- 45 ting'ei'lges of the active buckets, thus givinga finishing'tonch t'o'the excavating.

Hon-ever, while I have illustrated and described the road grader of my invention in'a highly '(lesiiralilc embodiment including certain advantageously arranged driving connections and adjustments, I do not wish to be limited'to these or other details of the construction and arrangement thus disch .11, it being obvious that'the same might be modified in many ways without departing from the spirit of my invention or from the appended claims.

I claim as my invention:

1. A road grader comprising a vehicle, a bucket excavator carried by the vehicle and operating transversely of the vehicle for s2;- csvating the -ro'adto a lei-'el at a predetermined depth iielow its previous grade, at levcling scraper behind the said excavating 'ineans,..a IjOlDIk'iOfififlI'liQ-l for the excavator til umspse andth'escraper-{and means for raising and loweringi the carrier so as'to simultaneously raise or lower "both the "excavating means a and the scraper.

2. 'A ioad scraper comprising a vehicle, means moving transversely of the vehicle for 'excavatingth'e road to'a level surface and elevating the-excavated soil, and means carried by the vehicle and engaging the road in front "of the said excavating means for resisting-the thrust of the latter laterally 0f the "vehicle.

3. A road scraper comprising a vehicle, 'ineans moving transversely 0f the vehicle for-excavating the road to a level surface and elevating theexcavated soil and nieans carried -by the vehicle in front of the said excavating :means and adjustable in height simultaneonsly with the excavating means fo r res istin'g the thrust exerted by the excavatingineahs.-'

- ?4. =A-rroad z'scraper comprising a vehicle, uneansunoving transversely 'of the vehicle for excavating the-road to a levelsurface and for elevating the excavated soil, and dislrh'arrows carried by the vehicle and disposed for'eng'aging 'the soil in front o f the said excavating means.

5. A road scraper comprising a vehicle, means moving transversely of the vehicle for-excavating the'road to a level surface and for elevating the excavated soil, disk harrows carriedby the'vohicle and disposed for-engaging the'soilin front of the said excavating -meai1s, and 'means for simultaneously raising or lowering the excavating 'means and the harrows.

'6. A ro'ad grader comprising-a vehicle, a bucket excavator -mounted on the front of the vehicle and operating transversely ofthe vehicle while the vehicle is in motion for excavating the soil-to a predetermined level and for-elevating the-excavated soil, the excavatorlieing trained over horizontal shafts and having its'buckets tapering forwardly so as to present cutting edges sloping upwards forwardly of the vehicle when taking their excavating cut.

'7. A "road grader comprising a vehicle, e :ca\-'a tin'g means mounted on the front of the vehicle and operating transversely of the vehicle for excavating the soil toa predetermined level and for elevating the excavated soil; a Series of cutters carried by the vehicle and spaced longitudinally of the vehicie from the excavating means and ar ranged for entering the surface portion of thesoil which is tobe escaivated, and means "for simultaneously raising and lowering the saidescavating nieans'and cutters.

8. A road grader comprising a vehicle, excavating means carried thereby and operating transversely of the vehicle while. the latter is in motion for excavating the soil to a predetermined level soil cuttin means lUu ' 10. In a road grader, a vehicle, means for cutting a plurality of slits in the surface of the road longitudinally of the vehicle, and

means operating transversely of the vehicle behind the slitting means and while the vehicle is in motion for excavating the slitted road portion.

11. In a road grader, a vehicle, means for cutting aplurality of slits in the surface of the road longitudinally of the vehicle, means operating transversely of the vehicle behind the slitting means for excavating the slitted road portion, and a scraper behind the excavating means.

12. In a road grader, a vehicle, means for cutting a plurality of slits in the surface of the road longitudinally of the vehicle, excavating means operating transversely of the vehicle behind the slitting means for excavating the slitted road portion, a scraper behind the excavating means, and means for simultaneously raising or lowering the said slitting and excavating means and the scraper.

13. A road grader comprising a vehicle, excavating means disposed in advance of the supporting Wheels of the vehicle and operating transversely of the vehicle, and means engaging the road in advance of the excavating means for resisting the thrust exerted transversely of the vehicle by the excavating means.

14. A road grader comprising a vehicle, excavating means disposed in advance of the supporting wheels of the vehicle and operating transversely of the vehicle, and a plurality of cutters engaging the road in advance of the excavating means and disposed for resisting the thrust exerted transversely of the vehicle by the excavating means laterally of the vehicle.

15. A road grader comprising a vehicle, excavating means at the front of the vehicle and operating transversely thereof, and a plurality of cutters engaging the road in advance of the excavating means and disposed for resisting the thrust exerted transversely of the vehicle by the excavating means, the said cutters being concaved in the opposite direction to that in which the excavating is effected by the said transverse operation of the excavating means.

16. A road grader comprising a vehicle, excavating means at the front of the vehicle and operating transversely thereof, and means for cutting the surface of the road ahead of the excavating means into strips longitudinal of the vehicle, to a lesser depth than that to which the road is excavated by the excavating means, and yielding means supporting the cutting means.

17. A road grader including a vehicle, a carrier vertically adjustable upon the front of the vehicle, excavating means carried by the carrier and operating transversely of the vehicle while the vehicle is in motion, a pair of arms pivoted to the carrier and extending forwardly thereof, a shaft carried by the said arms and extending transversely of the vehicle, and a plurality of disk cutters mounted on the shaft and disposed for slitting the soil in advance of the excavating means.

18. A road grader-including a vehicle, a carrier vertically adjustable upon the front of the vehicle, excavating means carried by the carrier and operating transversely of the vehicle while the vehicle is in motion, a pair of arms pivoted to the carrier and extending forwardly thereof, a shaft carried by the said arms and extending transversely of the vehicle, and a plurality of disk cutters mounted on the shaft and disposed for slitting the soil in advance of the excavating means, and spring means continuously pressing the said arms downwardly.

19. A road grader including a vehicle, a carrier vertically adjustable upon the front of the vehicle, excavating means carried by the carrier and operating transversely of the vehicle while the vehicle is in motion, a scraper fast upon the carrier and disposed behind the excavating means, and skid-preventing means yieldingly mounted on the carrier and disposed for engaging the road ahead of the excavating means.

20. A road grader comprising a vehicle, an endless assembly of excavator buckets mounted on the front of the vehicle and operating transversely of the vehicle while the latter is in motion, and guide means resisting the upward thrust of the buckets during the excavating, the said guide means including a plurality of rollers having axles extending longitudinally of the vehicle at substantially equal heights.

21. A road grader comprising a vehicle, excavating means actuable while the vehicle is in motion and operating transversely of the vehicle, means engaging the road surface for preventing the thrust of the excavating means from altering the course of the vehicle, and means for varying the extent of the said road engagement in proportion to the hardness of the soil.

22. A road grader comprising a vehicle. an endless system of excavator buckets operating transversely of the latter, means for guiuii'ig the excavating buckets in a rectilinear path means forv simultaneously propelling thjg vehicle and operating 'the buckets, carrier; mea ns mountqd on the vehicle: fgr;

buckets and suppgxted jointly, bythecan rier means and the; vehicle and separately contzol led means associated with the carrier meags abopposite sid@s;.o f ;the.- vehicle for 10 raising 0 1: loweringjthmcarrier, means.

Signfed atlIewton, Iowa Mays 23.,"1921.

CHARLES E. STAHL. 

